This invention relates to a developing apparatus for electrophotographic recording, and in particular to a toner container which contains toner in its cylinder-shaped container body and discharges the toner with rotation, and a toner replenishing device which is fitted with the container and replenishes toner therein to a toner storing portion by rotating the container.
Heretofore, there has been such type of means for replenishing toner from the toner container (toner cartridge) to the toner storing portion in the image forming apparatus as the following: every time when toner is to be replenished, the toner container is attached to the image forming apparatus to replenish whole toner in the container to the storing portion, and it is taken away from the apparatus mainframe after the replenishing is finished. However, in the above-mentioned type of replenishing method, the toner may overflow out of the storing portion in case of excessive replenishment, because the whole toner is fed at a time to the storing portion, and therefore some means must be provided for preventing the excessive replenishment.
It is difficult to prevent the above-mentioned excessive replenishment of toner, and although some means for preventing the excessive replenishment could be provided in the apparatus mainframe on occasion, it resulted in the higher-costed and larger-sized apparatus. Thus, it has been developed a device of the type that a toner container which has a coil-shaped protrusion inside is attached to the apparatus mainframe, and is rotated around its center axis to cause the toner to be discharged through a toner discharging opening to replenish the toner storing portion with it (Japanese laid open patent H7-295356 etc). This type of device has such advantage that any means for preventing the aforesaid excessive replenishment is not necessary, because the toner container is attached to the apparatus mainframe at all times, and it enables a timely replenishment of toner to the toner storing portion by rotating the toner container on occasion that the toner amount in the storing portion decreases.
However, in the above-mentioned toner replenishing device, the function is effected by mating the toner discharge opening provided at the end surface of the toner container with the toner receiving opening provided at the end surface of the toner storing portion, so that the exact positioning of the above-mentioned discharge opening and receiving opening is required. Moreover, it has such disadvantage that toner is easy to leak from the joint portion of the toner discharging opening and the toner receiving opening on exchanging the toner container. Further, the aforesaid toner container and the aforesaid toner replenishing device to be fitted with the toner container have many subjects to be considered such as how to feed efficiently the toner in its container to the toner storing portion.